Vertical batch furnace assembly

ABSTRACT

A vertical batch furnace assembly for processing wafers comprising a cassette handling space, a wafer handling space, and an internal wall separating the cassette handling space and the wafer handling space. The cassette handling space is provided with a cassette storage configured to store a plurality of wafer cassettes provided with a plurality of wafers. The cassette handling space is also provided with a cassette handler configured to transfer wafer cassettes between the cassette storage and a wafer transfer position. The wafer handling space is provided with a wafer handler configured to transfer wafers between a wafer cassette in the wafer transfer position and a wafer boat in a wafer boat transfer position. The internal wall is provided with a wafer transfer opening adjacent the wafer transfer position for a wafer cassette from or to which wafers are to be transferred. The cassette storage comprises two cassette storage carousels.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Patent Application Ser. No. 62/880,829, filed Jul. 31, 2019, and titled VERTICAL BATCH FURNACE ASSEMBLY, the disclosure of which is hereby incorporated by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to a vertical batch furnace assembly for processing wafers.

BACKGROUND

Vertical batch furnace assemblies may comprise a cassette handling space provided with a cassette storage for storing a plurality of wafer cassettes. The cassette storage may comprise a cassette storage carousel and an associated cassette handler. The cassette handler can place a cassette on a platform stage of the associated cassette storage carousel. The number of platform stages in the cassette storage carousel, and the possible amount of wafer cassettes which can be stored on a single platform stage, may vary depending on the desired storing capacity. Increasing the storing capacity of the known vertical batch furnace assembly may lead to a bigger apparatus which may be unwanted.

SUMMARY

This summary is provided to introduce a selection of concepts in a simplified form. These concepts are described in further detail in the detailed description of example embodiments of the disclosure below. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

It may be an object to provide a vertical batch furnace assembly with an improved storing capacity.

To that end, there may be provided a vertical batch furnace assembly. More particularly, there may be provided a vertical batch furnace assembly for processing wafers. The vertical batch furnace assembly may comprise a cassette handling space. The cassette handling space may be provided with a cassette storage configured to store a plurality of wafer cassettes provided with a plurality of wafers. The cassette handling space may be provided with a cassette handler configured to transfer wafer cassettes between the cassette storage and a wafer transfer position. The vertical batch furnace assembly may comprise a wafer handing space. The wafer handling space may be provided with a wafer handler configured to transfer wafers between a wafer cassette in the wafer transfer position and a wafer boat in a wafer boat transfer position. The vertical batch furnace assembly may comprise an internal wall separating the cassette handling space and the wafer handling space. The internal wall may be provided with a wafer transfer opening adjacent the wafer transfer position for a wafer cassette from or to which wafers are to be transferred. The cassette storage may comprise two cassette storage carousels.

By virtue of the cassette handler, which may be, amongst others, configured to transfer wafer cassettes between both of the two cassette storage carousels and the wafer transfer position, it may be possible to associate a single cassette handler to both cassette storage carousels. Having two cassette storage carousels next to each other in the cassette handler space may make a compact design possible. Thus the size of the vertical batch furnace assembly may be reduced, or the vertical batch furnace assembly may store more wafer cassettes, without needing more space to do so.

For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught or suggested herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

Various embodiments are claimed in the dependent claims, which will be further elucidated with reference to an example shown in the figures. The embodiments may be combined or may be applied separate from each other.

All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of certain embodiments having reference to the attached figures, the invention not being limited to any particular embodiment(s) disclosed.

BRIEF DESCRIPTION OF THE FIGURES

While the specification concludes with claims particularly pointing out and distinctly claiming what are regarded as embodiments of the invention, the advantages of embodiments of the disclosure may be more readily ascertained from the description of certain examples of the embodiments of the disclosure when read in conjunction with the accompanying drawings, in which:

FIG. 1 shows a schematic top/see through view of an example of a vertical batch furnace assembly according to the description;

FIG. 2 shows a schematic top/see through view of a cassette handling space of the example of the vertical batch furnace assembly of FIG. 1; and

FIG. 3 shows a schematic side view of the example of FIG. 1.

DETAILED DESCRIPTION OF THE FIGURES

In this application similar or corresponding features are denoted by similar or corresponding reference signs. The description of the various embodiments is not limited to the example shown in the figures and the reference numbers used in the detailed description and the claims are not intended to limit the description of the embodiments, but are included to elucidate the embodiments by referring to the example shown in the figures.

Although certain embodiments and examples are disclosed below, it will be understood by those in the art that the invention extends beyond the specifically disclosed embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the invention disclosed should not be limited by the particular disclosed embodiments described below. The illustrations presented herein are not meant to be actual views of any particular material, structure, or device, but are merely idealized representations that are used to describe embodiments of the disclosure.

As used herein, the term “wafer” may refer to any underlying material or materials that may be used, or upon which, a device, a circuit, or a film may be formed.

In the most general terms the present disclosure provides a vertical batch furnace assembly 10 for processing wafers, of which an example is shown in FIGS. 1-3. The vertical batch furnace assembly 10 may comprise a cassette handling space 26. The cassette handling space 26 may be provided with a cassette storage 14 configured to store a plurality of wafer cassettes 16 provided with a plurality of wafers. The cassette handling space 26 may be provided with a cassette handler 28 configured to transfer wafer cassettes 16 between the cassette storage 14 and a wafer transfer position 24. The cassette handler 28 may be embodied as a single cassette handler 28.

The vertical batch furnace assembly 10 may comprise a wafer handling space 30. The wafer handling space 30 may be provided with a wafer handler 32 configured to transfer wafers between a wafer cassette 16 in the wafer transfer position 24 and a wafer boat in a wafer boat transfer position (is another embodiment/figure).

The vertical batch furnace assembly may comprise an internal wall 20 separating the cassette handling space 26 and the wafer handling space 30. The internal wall 20 may be provided with a wafer transfer opening 22 adjacent the wafer transfer position 24 for a wafer cassette 16 from or to which wafers are to be transferred. The cassette storage 14 may comprise two cassette storage carousels 18.

The effects and advantages of the vertical batch furnace assembly 10 have been described in the summary section and these effects and advantages are inserted here by reference.

In an embodiment the two cassette storage carousels 18 may overhang the internal wall 20 and the wafer handling space 30. By overhanging the internal wall 20 and the wafer handling space 30, a footprint of the vertical batch furnace assembly 10 may be reduced. This means that the amount of expensive floor area needed to accommodate the vertical batch furnace assembly is reduced and thus the overall costs for the vertical batch furnace assembly 10 is also reduced.

In an embodiment the vertical batch furnace assembly 10 may be provided with a substantially rectangular footprint having two opposite short sides defining a width 36 of the vertical batch furnace assembly 10 and having two opposite long sides defining a length 38 of the vertical batch furnace assembly 10. The width 36 of the vertical batch furnace assembly 10 may be around 2.2 meter or less. The length 38 of the vertical batch furnace assembly 10 may be 5 meter or less, preferably 4 meter or less.

By having a substantial rectangular footprint, multiple vertical batch furnace assemblies 10 can be arranged adjacent to each other, thus making optimal use of available floor area. Adjacent vertical batch furnace assemblies with rectangular footprints may have no unused space in between them. A width 36 of less than 2.2 meter is beneficial in view of interchangeability with other vertical batch furnace assemblies, for example from other manufacturers/brands. A length 38 of 5 meter or less, preferably 4 meter or less, is beneficial for reducing the footprint altogether.

In an embodiment the cassette storage 14 may be configured to store 20 to 60 wafer cassettes 16.

In an embodiment the wafer cassettes 16 may be embodied as Front Opening Unified Pods (FOUPs). FOUPs are considered standard enclosures for wafers in the industry. Using FOUPs is advantageous for exchangeability of the wafer cassettes between the vertical batch furnace assembly 10 and other wafer processing machines.

In an embodiment the two cassette storage carousels 18, the cassette handler 28 and the wafer handler 32 may be provided in a space between a bottom side 40 of the vertical batch furnace assembly 10 and a horizontal plane 42 at a height 44 of around 2.8 meter above the bottom side 40. The vertical batch furnace assembly 10 may have a removable top cover 46 extending above the horizontal plane 42 at the height 44 of around 2.8 meter above the bottom side 40. The top cover 46 may close off a top opening 80 in a top wall 82 of the vertical batch furnace assembly 10 through which top opening 80 wafer cassettes 16 may extend which are placed at a top platform stage 70 of at least one cassette storage carousel 18 of the two cassette storage carousels 18.

By ensuring that the two cassette storage carousels 18, the cassette handler 28 and the wafer handler 32 remain below a height 44 of around 2.8 meter, these parts remain within reach of an operator for maintenance and can be transported in the normal operating position through the standard clean room doors. Furthermore, these parts can be shipped in an assembled state, without the need to split them for shipping in standard size containers. This means that the vertical batch furnace assembly 10 can be shipped in one piece and may therefore be assembled in the factory of the manufacturer of the vertical batch furnace assembly 10. Thus no extensive assembling on site may be needed which reduces the cost of installing the vertical batch furnace assembly 10.

In an embodiment the vertical batch furnace assembly 10 may further comprise at least one cassette in-out port 48. The at least one cassette in-out port 48 provides the entrance to and the exit from the vertical batch furnace assembly 10, for the exchange of wafer cassettes 16 between the vertical batch furnace assembly 10 and the outside world. The at least one cassette in-out port 48 may be provided in a wall 84 bounding the cassette handling space 26. Said wall 84 may be at or near the short side of the substantially rectangular footprint of the vertical batch furnace assembly 10. The cassette handler 28 may be configured to transfer wafer cassettes 16 between the cassette storage 14, the wafer transfer position 24, and the at least one cassette in-out port 48. Such a cassette handler 28 can handle all of the wafer cassette transfers within the cassette handling space 26. By using only one cassette handler 28, space which would otherwise be occupied by additional cassette handlers can be used for other purposes. Thus the size of the vertical batch furnace assembly 10 may be further reduced, or the vertical batch furnace assembly 10 may store even more wafer cassettes 16.

In an embodiment the cassette handler 28 may be provided with a cassette handler arm 50, and an elevator mechanism 52 configured to reach wafer cassettes 16 at different vertical heights within the cassette storage 14.

In an embodiment the vertical batch furnace assembly 10 may further comprise a cassette door opener device 54. The cassette door opener device 54 may be placed at or near the wafer transfer position 24. The cassette door opener device may be configured to open a cassette door of a wafer cassette 16 which is placed in the wafer transfer position 24. The cassette door opener device 54 may thus automatically open a cassette door of a wafer cassette 16 which is placed in the wafer transfer position 24.

The vertical bath furnace assembly 10 may be a part of a production process in a clean room. The wafer cassettes 16 provided to and coming from the vertical batch furnace assembly 10 may therefore be used in other wafer processing machines. Having the ability to automatically open a cassette door of these wafer cassettes 16, makes it possible to use wafer cassettes which are provided with these cassette doors. This increases the exchangeability of wafer cassettes 16 between the vertical batch furnace assembly 10 and these other wafer processing machines.

In an embodiment the vertical batch furnace assembly 10 may further comprise a process chamber 56, 58 configured to process wafers.

In an embodiment each cassette storage carousel 18 may comprise a central vertical support which is rotatable around a vertical carousel axis. Each cassette storage carousel 18 may also comprise a number of platform stages 70 connected to the central vertical support for supporting a number of wafer cassettes 16. Each cassette storage carousel 18 may further comprise a drive assembly. The drive assembly may be operatively connected to the central vertical support for rotating the central vertical support with the number of platform stages 70 around the vertical carousel axis.

Although illustrative embodiments of the present invention have been described above, in part with reference to the accompanying drawings, it is to be understood that the invention is not limited to these embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this description are not necessarily all referring to the same embodiment.

Furthermore, it is noted that particular features, structures, or characteristics of one or more of the various embodiments which are described above may be used implemented independently from one another and may be combined in any suitable manner to form new, not explicitly described embodiments. The reference numbers used in the detailed description and the claims do not limit the description of the embodiments nor do they limit the claims. The reference numbers are solely used to clarify.

LEGEND

-   10—vertical batch furnace assembly -   14—cassette storage -   16—wafer cassette -   18—cassette storage carousel -   20—internal wall -   22—wafer transfer opening -   24—wafer transfer position -   26—cassette handling space -   28—cassette handler -   30—wafer handling space -   32—wafer handler -   36—width (of the vertical batch furnace assembly) -   38—length (of the vertical batch furnace assembly) -   40—bottom side -   42—horizontal plane -   44—height -   46—top cover -   48—cassette in-out port -   50—cassette handler arm -   52—elevator mechanism -   54—cassette door opener device -   56—first process chamber -   58—second process chamber -   70—platform stage -   80—top opening -   82—top wall -   84—wall 

1. A vertical batch furnace assembly for processing wafers comprising: a cassette handling space provided with a cassette storage configured to store a plurality of wafer cassettes provided with a plurality of wafers, and a cassette handler configured to transfer wafer cassettes between the cassette storage and a wafer transfer position; a wafer handling space provided with a wafer handler configured to transfer wafers between a wafer cassette in the wafer transfer position and a wafer boat in a wafer boat transfer position; an internal wall separating the cassette handling space and the wafer handling space and provided with a wafer transfer opening adjacent the wafer transfer position for a wafer cassette from or to which wafers are to be transferred, wherein the cassette storage comprises two cassette storage carousels.
 2. The vertical batch furnace assembly according to claim 1, wherein the two cassette storage carousels overhang the internal wall and the wafer handling space.
 3. The vertical batch furnace assembly according to claim 1, provided with a substantially rectangular footprint having two opposite short sides defining a width of the vertical batch furnace assembly and having two opposite long sides defining a length of the vertical batch furnace assembly, wherein the width of the vertical batch furnace assembly is 2.2 meter or less.
 4. The vertical batch furnace assembly according to claim 3, wherein the length of the vertical batch furnace assembly is 5 meter or less.
 5. The vertical batch furnace assembly according to claim 1, wherein the cassette storage is configured to store 20 to 60 wafer cassettes.
 6. The vertical batch furnace assembly according to claim 1, wherein the wafer cassettes are embodied as front opening unified pods (FOUPs).
 7. The vertical batch furnace assembly according to claim 1, wherein the two cassette storage carousels, the cassette handler and the wafer handler are provided in a space between a bottom side of the vertical batch furnace assembly and a horizontal plane at a height of around 2.8 meter above the bottom side.
 8. The vertical batch furnace assembly according to claim 7, wherein the vertical batch furnace assembly has a removable top cover extending above the horizontal plane at the height of around 2.8 meter above the bottom side, which top cover closes off a top opening in a top wall of the vertical batch furnace assembly through which top opening extend wafer cassettes which are placed at a top platform stage of at least one cassette storage carousel of the two cassette storage carousels.
 9. The vertical batch furnace assembly according to claim 1, further comprising at least one cassette in-out port provided in a wall bounding the cassette handling space, wherein the cassette handler is configured to transfer wafer cassettes between the cassette storage, the wafer transfer position, and the at least one cassette in-out port.
 10. The vertical batch furnace assembly according to claim 1, wherein the cassette handler is provided with a cassette handler arm, and an elevator mechanism configured to reach wafer cassettes at different vertical heights within the cassette storage.
 11. The vertical batch furnace assembly according to claim 1, further comprising a cassette door opener device placed at or near the wafer transfer position, and configured to open a cassette door of a wafer cassette which is placed in the wafer transfer position.
 12. The vertical batch furnace assembly according to claim 1, further comprising: a process chamber configured to process wafers.
 13. The vertical batch furnace assembly according to claim 1, wherein each cassette storage carousel comprises: a central vertical support which is rotatable around a vertical carousel axis; a number of platform stages connected to the central vertical support for supporting a number of wafer cassettes; a drive assembly which is operatively connected to the central vertical support for rotating the central vertical support with the number of platform stages around the vertical carousel axis. 